Electric brake for hoists.



H. S. VALENTINE.

ELECTRIC BRAKE FOR HOISTS.

APPLIGATION FILED JULY s1, 1912.

1,060,384, Patented Apr. 29, 1913.

2 SEEETS*SHEET 1.

a@ @VM lt/www FIG? 2 H. S. VALENTINE.

ELECTRIC BRAKE POR 'Horsfm APPLICATION FILED JULY 3l, 191% Patented M1129, 1913 2 SHBETS-SHBET 2.

PATENT oEEIcE.

c UNITED sTATEs HERBERT S.V VALENTINE, F READING, PENNSYLVANIA, ASSIGNOB T0 READING CRANE HOIAST WORKS, 0F READING, PENNSYLVANIA.

ELECTRIC BRAKE AEon IHors'rs.

Specification of Letterslatent.

Application led July 31,

1912. serial Ne. ariane?.y

Beading, in-the county of Berks and .State I of Pennsylvania, have invented certain new and useful Improvements inElectric Brakes ,for Hoists, of which the following is a speciication.

My invention particularly relates toelectrically actuated4 brakes, and is especially applicable 4to automatically controlled brakes for electric hoists, wherein itis essential that the winding drum beprevented from rotation to hold theload when not actuated by the driving mechanism.

, The principal objects of my invention are to provide. an automatically controlled electric brake which is simple in construction and elicientin its actuation.

Other objects of my invention are to provide an electric brake arranged to be electrically connected with the circuit of the driving motor and having its parts so correlated as to readily respond to t-he opening and closing of the motor'circuit'.

Briefly stated, my inventionincludes pivf oted levers having diametrically opposed brake shoes coperative with the brake drum to prevent the rotation of the motor shaft, and normally actuated by spring pressure tendingr to engage the shoes with said drum, said shoes being released by a solenoid electrically connected to be actuated contemporaneously with the driving motor, and mechanically connected with the levers carraying the shoes, by rocking levers pivoted on stationary axes and having long and short arms upon opposite sides of their axes, the longer arms being pivotally connected with the core ot said 'solenoid and the shorter arms being pivotally connected to said shoe carrying levers.

This invention also comprehends all of the various novel features of construction and arrangementv of the parts hereinafter more definitely speciiied.

In the accompanyln drawings, Figure 1 is a front elevationa view of the brake mechanism constructed in accordance with myv invent-ion, ar. conveniently secured to the casing of the motor or other mechanism i which it is arranged to control; Eig. 2 is a side elevational view of the structure shown in Fig. l, and including a fragment of the motor casing.; Fig. is a sectional plan view line 3-,3 in Fig. 1, and Fig. 4 is a cent-ral vertical sectional view of the solenoid takeny E the line 4-4 in Fig. 3.

i motor or other rotary mechanism which may z be included in the casing 6, and which carries the brake' drum 7, is conveniently journaled in the bearing 8, having the oil cup 9 :carried thereon, for supplying suitable lubricant tol saidyshaft.

The solenoid 10,` which is operative torelease the brake mechanism, has the bracket 13 to the-'end 14 of the casing 6 and comprises the coils 15 and core 16 avin the plunger 17 carried therebyv and providmg 'a reduced support 18 lforming al shoulder 19 as best shown in Fig. 4 for the crosshead 20, which as shown in Fig. 5- is secured thereon by the pin 21.

The casing of the solenoid 10 is provided with an upwardly extending lug 23 which 26 respectively, having the diametrically opposed broadened substantially semi-cylinspectively provided with frictional facings 30V and 31 formed of leather, fiber or other cylindrical surface of the brake drum 7 255 and 26, as best shown in Fig. 1, are relatively close land ali'ord a quick, free separation of the frictional facing 30 from the cyends of the brake levers are relatively shi ted apart.

The free ends of the brake levers 25 and 26 are respectively provided with cups or sockets 36 and 37 opening op ositely and having apertures -38 and 39, t rough which the spring spindle 40 extends. The spring spin dle 40 carries the plates or Washers 41 and 42 relatively adjustablel to vary the tension of the springs 43 and 44 seated in the respective sockets 36 and 37, bythe adjusting nut 45, which is arranged to be secured in adjusted position by the lock-nut 46. The springs 4 3 and 44 are held"`under sufficient lcompression to normally maintain the facfrictional engagement with the 'brake drum 7 as to preventits rotation until said levers 11 rsecured by the nuts 12 on the stud bolts pivotally supports the brake levers 25 andv lindrical surface of the drum? when the fr e v Patented Apr'. 29.19.13..

of the brake mechanism per se, taken en the'. i

through one of itsielectrical connections on In said figures, the shaft-'5 of an electric drical brake shoes 28 and 29 which are rematerial suitable to frictionally engage the f The fulcrums 33 and 34 of the bra-ke levers ings 30 and 31 of the shoes 28' and 29 in such 25 and 2G are shifted in opposition to the spring pressure by a novel arrangement of lever mechanism to be hereinafter described in detail. i.

The release 'of the brake drum 7 is conveniently eected by the rocking levers 47 and 48, which are preferably fulcrumed on the pivots 50 and 5l carried by the lugs 52 and 53 extending laterally from the casing of the solenoid 7. Said rocking levers 47 and 48 respectively have their'long arms pivotally connected at 54 and 55 with the crosshead 20, and their short arms pivotally connected lever mechanism, the brake levers 25 and Q6 may be rocked outwardly on their respective fulcrnms 33 and 34 to overcome the tension of the springs and 44, and release the brake drum 7 by 'comparatively litt-le power exerted by the solenoid, i x

'The solenoidl() is conveniently provided v withtheiermnals. 60 and 6l which may be mountedjin the insulated bushings 62 and 6 3 and respectively- 'connected .by the leading .Wires 64 'and-65 With suitable controlling means, Whichmay-'be effective to simultaneously lcontrol said'solenoid and the motor which eifects the rotation of the brake drum '7ivwhereby the brake may be automatically released When the motor isr actuated "and aplplied When said motor stops. It is not desired to limit myself to the precise details `of construction and arrange- Lacasse ment of the parts as herein. set forth, as various modifications may be made therein Without departing from the essential features of the invention as defined in the appended claim.

Having thus described my invention, l claim: f

In an electric brake, the combination of a brake drum, a motor shaft, a pair of rocking` levers, a pair of pivoted brake levers having diametrically opposed brake shoesl coperative With the drum to prevent the rotation of the motor shaft, springs tending to norl mally press the shoes against the drum, a

solenoid having an upwardly extending central lug and a vertically movable core for releasing the shoes from Contact with the drum, said solenoid being electrically connected to be actuated contemporaneously V with the'motor shaft and mechanically connected Yby the rocking levers with the brake levers, said brake levers being pivotally connected to the central lug on the solenoid in close proximity to the vertical center of the solenoid, oppositely disposed lugs extending laterally from the solenoid casing, said rock`v ing levers being pivoted to said lateral lugs and having long arms in pivotal connection With the solenoid core and short arms on the y opposite sides of their pivotal connection with the lugs which. short arms are pivotally connected With the bra-ke levers, ,all of Which pivotal points are on the same horizontal plane, whereby a very slight upwardmovement of the solenoid core Will effect the re lease of the shoes from contact with the drum and compress the springs.

In testimony whereof I aflix my signature in presence of two Witnesses.

HERBERT SQVALNTINE. lVitnessesf IMARY E. S'rAUFFER,

En. ,A. KELLY.

`v lv 

